Sadly, this .deb application not seem to install under porteus thru deb2xzm only. It is devised for systemd. I will have to work with debian (slax9), until I get the trick to slackware. Nothing found yet on the net.

2.0 Download expressvpn server location or locations addresses:https://www.expressvpn.com/setup#manual
for example for montreal :my_expressvpn_canada_-_montreal_udp.ovpn
Open terminal, but do not enter command yet:
root@porteus:/home/guest/Downloads# openvpn --config
Copy-paste the downloaded expressvpn server address or simply drag it to the terminal window. Remove the quotes character at each end of the address.
Now hit the enter button. You will be requested user name and password.

3.0 Enter user name and password.
Find your email confirmation of service for expressvpn. Select setup expressvpn, manual config, openvpn config.
Go to step 2 , as we already done step one by downloading an expressvpn server location address. Both username and password are there.

The problem is that you have to have the openvpn active with username and password to have the expressvpn google chrome app to work. This is not the case under the debian application which seems to be in synch with the chromium app.

Hey Francois! Have you ever tried ivacy VPN? I have been using it for a long time and believe me I never faced any issue regarding the connection speed. I would highly recommend you giving it a try after knowing the facts and fundamentals through this ivacy VPN Review. It will guide you in a better way to decide what it has to offer.

Hum! I saw this page and tried it on debian. I ended up with unresolved dependencies.
But you are right, it might work better under slackware or porteus.
Thanks.

Edited 13th of february 2018:
Finally, the best way to get the information of IVACY about .opvpn files was to ask them. They responded rapidly. So you need to install the openvpn package with dependencies as proposed in the first page of this thread Which VPN provider do you recommend?

Unzip OpenVPN-Configs.zip into /home/guest/Downloads/ and change directory the folder with the server addresses. Use openvpn --config command with the server.ovpn file name into quotes. Or simply drag the sever file into the command line after the expression: